Question

How do you solve `2j/7 - 1/7 = 3/14`?

Answer 1

Rewrite with a common denominator or multiply through to remove the denominators then solve using standard arithmetic manipulations.

Explanation:

Note that there are two possible answers depending upon the interpretation of `2j/7`

Interpretation 1 : `2j/7` is intended to be a multiplication: `2(j/7)`
`2(j/7) - 1/7 = 3/14`
If we multiply all terms on both sides by `14` we get
`color(white)("XXXX")` `4j - 2 = 3`
`color(white)("XXXX")` `rarr j = 5/4`

Interpretation 2: `2j/7` is intended to be a mixed fraction`2+(j/7)`
(It is unusual, but not impossible, that a variable is part of a mixed fraction).

`2+(j/7) - 1/7 = 3/14`
Again, if we multiply all terms on both sides by `14` we get
`color(white)("XXXX")` `28 +2j -2 = 3`
`color(white)("XXXX")` `rarr 2j+26 = 3`
`color(white)("XXXX")` `rarr 2j = -23`
`color(white)("XXXX")` `rarr j = -23/2`